The core reference counting code is centralized in p_refcnt.h.
This has some consequences related to struct pipe_buffer:
* The screen member of struct pipe_buffer must be initialized, or
pipe_buffer_reference() will crash trying to destroy a buffer with reference
count 0. u_simple_screen takes care of this, but I may have missed some of
the drivers not using it.
* Except for rare exceptions deep in winsys code, buffers must always be
allocated via pipe_buffer_create() or via screen->*buffer_create() rather
than via winsys->*buffer_create().
Instead, a new pipe_transfer object has to be created and mapped for
transferring data between the CPU and a texture. This gives the driver more
flexibility for textures in address spaces that aren't CPU accessible.
This is a first pass; softpipe/xlib builds and runs glxgears, but it only shows
a black window. Looks like something's off related to the Z buffer, so the
depth test always fails.
this change disassociates, at least from the driver perspective,
the surface from buffer. surfaces are technically now views on the
textures so make it so by hiding the buffer in the internals of
textures.
allows the driver to overwrite buffer allocation, first step on the way
to making winsys interface internal to the drivers. state trackers and
the code above it will go through the screen
This commit is mostly just a cosmetic change that cleans-up the interfaces,
replacing pipe_winsys::surface_* calls by
/**
* Allocate storage for a display target surface.
*
* Often surfaces which are meant to be blitted to the front screen (i.e.,
* display targets) must be allocated with special characteristics, memory
* pools, or obtained directly from the windowing system.
*
* This callback is invoked by the pipe_screenwhen creating a texture marked
* with the PIPE_TEXTURE_USAGE_DISPLAY_TARGET flag to get the underlying
* buffer storage.
*/
struct pipe_buffer *(*surface_buffer_create)(struct pipe_winsys *ws,
unsigned width, unsigned height,
enum pipe_format format,
unsigned usage,
unsigned *stride);
Most drivers were updated but not all were tested. Use the softpipe pipe
driver and the xlib winsys changes as a reference when fixing other drivers.
When a surface is created with GPU_WRITE that really means "GPU render"
and that can involve reads (blending). Set surface usage to
PIPE_BUFFER_USAGE_CPU_READ + WRITE. Fixes progs/demos/lodbias demo.
Also, mark texture as 'modified' when mapped for writing so that the tile
cache can know when to freshen a cached tile. Fixes glTexSubImage2D().
For many envirionments it's necessary to allocate display targets
in a window-system friendly manner. Add facilities so that a driver
can tell if a texture is likely to be used to generate a display surface
and if use special allocation paths if necessary.
Hook up softpipe to call into the winsys->surface_alloc_storage()
routine in this case, though we probably want to change that interface
slightly also.
